The primary task of light devices of motor vehicles is to light the carriageway or to emit light signal functions. However, at present there is an increasing focus on significantly higher involvement of headlights and signal lamps in the designer concept of the vehicle. Light devices should not only emit light with the required radiation characteristic, but at the same time they should participate in the character of the vehicle.
A light device of motor vehicles comprises at least one lighting unit ensuring, or contributing to ensuring the required emission characteristic of the light trace. Individual lighting units are generally mounted in a shaped carrying bushing of the lamp while each unit contains at least one light source and other optical elements. The light source emits light rays and the optical elements represent a system of refractive and reflective surfaces and interfaces of optical environments that influence the direction of light rays within the creation of the output light trace.
Lighting devices are known from the prior art that are adapted to create various patterns and spatial effects. E.g. the document EP1126209 discloses a lighting device comprising a light guiding optical element adapted to combine the light generated by two different light sources, the device making it possible to emit a different light pattern in the lit state. A disadvantage of the above-mentioned solution consists in limited designer options because designer requirements for the external appearance of the product cannot be met, e.g. it cannot actively create light patterns with a spatial effect in the lit state and in the off state, when the optical elements do not provide a spatial impression. Thus, 3D effects cannot be produced when the light source has been switched off.
The document CZ20150002 discloses the design of a signal lamp that comprises a spatially shaped light guide the parts of which, especially the output surfaces, overlap each other in the view of the inner space of the headlight, which makes it possible to produce a spatial effect, e.g. in the form of spatially arranged crystals, even after the light source being switched off. A disadvantage of this design is the fact that the spatially shaped light guide occupies a considerable installation space, is expensive to produce and does not allow more light functions to be combined.
The document WO2016/064205 discloses a lighting apparatus capable of providing three-dimensional effects at the same time as the surface emission of light sources by using a half-mirror member for reflecting and transmitting parts of light. In particular, by adopting the half-mirror member for transmitting a part of and reflecting another part of light emitted from a surface-emitting light source module, this device allows the implementation of a mirror-like image when the light is off, and allows the implementation of a light image providing various three-dimensional effects when the light is on.
The document WO0141455 discloses a soft edge plate for use in the projection of an image onto a viewing screen. It comprises a transparent area, an opaque area, and a semi-transparent area between said transparent area and said opaque area. The semi-transparent area comprises an alternating macroscopic pattern of discrete opaque and transparent areas. A soft edge plate with a pattern as described above, applied in metal on a glass substrate, may in particular be used for soft edging LCD projectors.
The object of the invention is to design a light device, especially a signal lamp for motor vehicles, that can be adapted to designer requirements for the external appearance of the product, wherein the light device should, besides emitting light, participate in the designer character of the vehicle while in the off state, such that the spatial impression should be maintained.